Brittany Nelms

Nelms will present her exit seminar on "Overwintering Biology of Culex Mosquitoes in California and Their Potential Role as Overwintering Reservoirs of West Nile Virus" from 12:05 to 1 p.m., Wednesday, May 8 in Room 1022 of the Life Sciences Addition, corner of Hutchison and Kleiber Hall drives.

She will be introduced by her major professor, William Reisen of the  Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, and research entomologist with the Center for Vectorborne Diseases.

Nelms finished her doctoral work in entomology, emphasis in the biology of vectorborne diseases, last December. As the LCVCD entomologist, she helps plan and conduct the district’s research and surveillance program for various arthropod vectors and vectorborne diseases.

Nelms has  presented and published many articles in the Proceedings and Papers of the Mosquito and Vector Control Association of California and co-authored several peer-reviewed publications.  She published her first primary author, peer-reviewed research paper, "Experimental and Natural Vertical Transmission of West Nile Virus by California Culex (Diptera: Culicidae) Mosquitoes,” in the March, 2013 issue of the Journal of Medical Entomology. 

As a graduate student at UC Davis, she received the William C. Reeves New Investigator Award from the Mosquito and Vector Control Association of California; the Bill Hazeltine Student Research Award; and recently was the runner-up for first-place in the American Mosquito Control Association's Student Paper Competition.

“My dissertation research addressed the overarching hypothesis that West Nile virus (WNV) persists within infected, overwintering Culex females until the termination of diapause and/or quiescence renews blood feeding and horizontal transmission,” Nelms said in her abstract. “I addressed this hypothesis with three specific aims. 

“First, the persistence of WNV during winter in mosquito hosts was explored by determining the overwintering strategies of Culex females, delineating the environmental cues utilized in the induction and termination of diapause, and detecting WNV in field-collected overwintering mosquitoes. 

“Secondly, the ability of California Culex females to vertically and transstadially transmit WNV to overwintering progeny was investigated during autumn to determine the frequency of field infection and vertical transmission at foci of active WNV transmission. 

“Third, the vector competence and biology of Culex pipiens f. molestus and f. pipiens females were compared in the laboratory to determine their respective roles as amplification and overwintering vectors of WNV.   Overall, I found that Culex tarsalis and Culex stigmatosoma entered and maintained diapause under both field and experimental conditions, whereas members of the Culex pipiens complex remained reproductively active (f. molestus) or entered quiescence (f. pipiens).  All species were competent vectors of WNV and able to transmit both horizontally and vertically.   Therefore, WNV may overwinter in infected Culex that remain reproductively active, enter reproductive diapause or become quiescent during cool weather.”